SP546 vs SP515

The spark plug plays an important role in a positive-ignition engine. It ignites a mixture of air and fuel that comes from a spark. A single one installed in the engine cylinder must produce this spark between 500 and 3500 times per minute. Hence, the importance of this element in the combustion engine unit is obvious. Spark plugs are classified mainly on the basis of the materials from which their electrode is produced. Usually, the cheapest ones are made of nickel alloy. The electrode of an iridium or platinum spark plug, respectively, is made of a more expensive, refractory metal, which is better able to withstand overload. 

The main difference is their service life. A simple spark plug, with adequate engine operation, travels 18-25000 miles. Iridium and platinum ones are twice as big. But the cost of such elements will be much higher. 

It’s best to stick to the regulations established by the manufacturer. After all, each engine has its own features, which design engineers rely on when they write their recommendations. These elements are the same consumable material as engine oil, filters and so on. Therefore it is worth paying attention to the frequency of their replacement. But there’s a nuance to it. It happens that the engine, for example V6, has a transverse arrangement. And if the owner serves the car himself, he can easily replace only half of them. To get to the other, in other cases, you have to disassemble half of the car.

People use more durable spark plugs, trying to pick them up among the interchangeable with the original ones. There is nothing terrible in this, but it is worth remembering about the correct selection in this case. Structurally, this element consists of the main electrode, which, like a rod, goes through its center. There’s also a side electrode. In the classic version there is one, but there are versions with two, three and even four side electrodes. Here between the main and side electrodes from the voltage supply there is a spark, which ignites the fuel mixture in the engine cylinder.

sp 514 vs sp 515

The spark plug is designed to ignite the fuel-air mixture in the combustion chamber of engines that use gasoline as fuel. It is used in diesel motors.

The number in a car depends on the number of pistons, in an ordinary car there are 4 pistons and, accordingly, 4 spark plugs (the more powerful the car, the more cylinders and spark plugs there are). There are spark plugs in the head of the cylinder block. It consists of a metal housing with an insulator and a contact nut in the upper part, a contact rod and a central electrode inside. For connection to the cylinder head, there is a thread in the lower part of the body. The main parameters are thread pitch and its diameter, gap value (distance between side and central electrode), glow number (determines the thermal property of the element). Each engine (car) has its own values for these parameters. Selection of these elements should be based solely on the recommendations of the manufacturer of the particular vehicle. In addition, they should be replaced with a set, i.e. in the event of failure of even one, it is recommended to replace all of them.

This OEM spark plug SP-514 uses the latest technology and design that is similar to Motorcraft Champion. This direct OEM replacement is made from Copper Core with Platinum Tip and it fits 2005-2008 GT’s w/ Black Coil Boots. SP 515 one is not a stock item and is used on roush charged motors.

SP509 vs SP515

So, you decided to buy a spark plug. The seemingly identical parts can be completely different. In order not to make a mistake, consider the following:

  • The type of wire connection. It could be a thread, a latch, or a universal high-voltage wire connection;
  • Potassium number. 
  • The size of the threaded part. Compare a new item to an old one. It must fit he diameter, length and necessarily the thread pitch;
  • The width of the hexagon. Essentially, the old and new ones must have the same turnkey size.

You may also encounter a choice of these items with different mass electrodes. Usually they are executed in the shape of the letter “G”. Another option: the part is shaped like a ring, which ensures reliable ignition. Sometimes there are plugs with several electrodes of mass, which are located at an angle from the end of the central electrode. All variants are good, if it was chosen correctly.

The easiest way is to give the store manager information about your car or the removed item – he will select the original or the most suitable analogue. Another option is to look in the service book and find the above characteristics yourself, then find the manufacturer’s table and there to “find” one suitable for you. Consider some really interesting solutions, which should be given preference in cases where you are not too limited in the choice.

SP515 is a platinum one, its predecessor is SP 509. The original ones were the SP507. However, SP 509 is still a valid number. SP509 plug is a 1 piece that fits 08+ 5.4 redesigned heads.

Editorial Staff

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